Negative LTFT Problems.

Jwayne

Greenie N00B Member
Hey guys I need some help to give some context I have a 2013 tech package ms3 with a BOV, Auto tech HPFP, muffler delete and everything else is stock. I also have a Cobb accesport that I track my car with. I noticed that my ltft goes up into the negatives after I do some pulls. For example when I am cruising I am around -7.81 and when I go WOT it goes to -2.34 or -1.56 sometimes even 0, after a couple hard pulls it goes to -9.83 on idle and cruise and settles till I drive normally again and goes back to the -8 and -7 areas. I heard even at cruise -7.81 is still high should I be looking for leaks? Boost is holding stock psi 15.3, Afr Is 14.7 on idle, HPFP pressure is 430.

Thank you for any help.
 
this thread talks about some parameters
https://mazdaspeeds.org/index.php?threads/accessport-v3-parameter-monitoring.9757/#post-75719
Pre-turbo = + trims, air added or sucked in
turbo to TP = - trims, air lost or pushed out
post TP = + trims, air added or sucked in

+5 or -5 is ideal
+7 or - 7 not crazy might want to look into it
+10 or -10 look into it , you got a leak
+20 or -20 shits broke yo
at that +/-7 range it's okay seeing 9 is not, 8 I'd look into you want to look at LTFT during cruise and idle with AC off. if it changes with AC on then that could also be a dirty air filter on folks running a Short ram intake.
I'd be inclined to do a boost leak test
 
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